Explained: Molnupiravir, the drug shown to stop Covid-19 spread in 24 hrs

This is the first demonstration of an orally available drug to rapidly block SARS-CoV-2 transmission and it can be a game-changer, said Dr Richard K Plemper, Distinguished University Professor. The group led by Dr Plemper originally discovered that the drug is potent against influenza viruses. “We have characterized the MoA (mechanism of action) of Molnupiravir against influenza viruses in an earlier publication,” Dr Plemper told The Indian Express by email.

Its action: In ferrets, the drug was shown to completely suppress transmission of SARS-CoV-2 in 24 hours. Researchers infected ferrets with SARS-CoV-2 and initiated treatment with MK-4482/EIDD-2801 when the animals started to shed the virus from the nose. “When we co-housed those infected and then treated source animals with untreated contact ferrets in the same cage, none of the contacts became infected,” said Josef Wolf, co-lead author of the study.

However, all contacts of source ferrets that had received placebo became infected. The exciting development was that it completely suppressed the spread to untreated contact animals. According to researchers, if these ferret-based data translate to humans, Covid-19 patients treated with the drug could become non-infectious within 24 hours after beginning treatment.

Why ferrets: Ferrets are a popular model for influenza and other respiratory infections because their lung physiology is similar to humans and researchers hope they will mimic aspects of Covid-19 in people such as its spread. “They readily spread SARS-CoV-2 but mostly do not develop severe disease – closely resembling the infection spread in young adults,” said Dr Robert Cox, co-lead author.

Human trials: “The drug basically stops replication of the copies of the virus’s RNA in the cell,” said Dr Shekhar Mande, Director General Council of Scientific and Industrial Research. “The drug is like any other anti-flu drug and was on our list of drugs to go into clinical trials. There are several promising drugs and they are under evaluation… We have also in principle decided to go ahead with the clinical trials for testing Molnupiravir in humans and will apply to the regulator for approval.”

Globally, Ridgeback Biotherapeutics is running clinical trials in collaboration with Merck. The drug is now in advanced phase 2/3 human trials at multiple centres. The phase 2/3 trial is a randomised, placebo-controlled double-blind clinical study to evaluate the efficacy and safety of MK-4482 in hospitalised adults with Covid 19 across 46 locations in various countries as well as in non-hospitalised patients. 📣 Follow Express Explained on Telegram